Meditations 8:48

Remember that when it withdraws into itself and finds contentment there, the mind is invulnerable. It does nothing against its will, even if its resistance is irrational. And if its judgment is deliberate and grounded in logic . . . ?

The mind without passions is a fortress. No place is more secure. Once we take refuge there we are safe forever. Not to see this is ignorance. To see it and not seek safety means misery.